two stage prossecing with a gl

[willbuild]

read up on it on wiki,  if i put the glycerol back in after the 1st stage surely I'm making it harder for for the last bit of oil to be converted. thought the point of removing the glycerol was to make it easier to reach tipping point.
the first batch i made, by error i only put 50%of the Noah necessary. removed the glycerol. when i did a 3/27 test i noticed that 1part of the 3 of oil used in the test had not been converted. so added 30% more Noah with 5 litres of methanol and re processed without putting the glycerol back in. I got half the amount of glycerol out than i did on the first stage.
73 litres of wvo went in and 76 litres of bio came out passing the 3/27 test staying crystal clear at all times. should Ive put the glycerol back??

[Julian]

Two stage processing is probably the easiest way to achieve a complete conversion.

Stage one should be run with 80% of the methoxide and the glycerine allowed to settle.

Drain the stage one glycerine getting as much out as possible.  Try draining until you reach bio, then go away and have a cup of tea for half an hour and drain again.  You'll be surprised at how much glycerine clings to the processor walls and runs down after you think it's all out.

Then run the second stage with the remaining methoxide.  Once you achieve a 3/27 pass you can add back the first stage glycerine.  Demeth at this point if you wish to reuse the reclaimed methanol, you can 7% prewash after that.

Alternatively you can settle and drain the second stage glycerine if you wish to use it to glycerine wash your next batch of oil.

[willbuild]

ok, I understand now, the gycerol is added back to the mix after stage 2 reaction is compleat and only if it passes 27/3 test, demeth then pre wash. 5% or 7%?
thank you again for your help my last batch is now clear, will give it another 48 hrs before doing a 50/50 test

[RichardP]

If you want to use the glyc to in the next batch then don't add it back in after stage 2, you can still do a 7% prewash with whatever glyc is in after the second stage. Introduce the water slowly through the venturi and you should get a good result.

Using glyc that's been used in a 7% pre-wash is no where near as effective at cleaning up and drying oil in the next batch.